The present invention relates to centrifugal fans, and more particularly to a centrifugal fan of the type having an impeller driven by a motor and supported for rotation in a housing. The blades of the impeller define passages for centrifugally expelling fluid received through an inlet of the housing towards an outlet of the fan thus forming a high pressure at a required speed.
The centrifugal fans of the foregoing type are known in the art. In the known constructions of the centrifugal fans the fan is provided with a static pressure regulating antechamber which is separated from a main diffusing chamber formed in the interior of the fan housing by a space surrounding the impeller's blades.
In such constructions it is known that the operating curves of the centrifugal fans are continuous and have a uniform line, thus corresponding to given conditions of established operation output such as the desired pressure and efficiency of the fan.
The constant difficulty experienced in the known arrangements lies in obtaining a higher flexibility in the operation of the known machines.